Fish Tank Urine Filters What Could Of Caused My Betta Fish To Have Died?

What could of caused my Betta fish to have died? - fish tank urine filters

I have it from PetSmart in December 2007. He had a 5 gallon tank with a heater and a filter. I water change Weekley. I feed him pellets and brine shrimp. I noticed the color gray about 2 months earlier purple everywhere was white and his chin was new in this month. Yesterday I noticed the water was yellow, almost the color of urine. Then he noticed it was a kind of network failure (not) dead in their aquarium. I have a water change last night and woke up this morning, had disappeared. During the last few months, he spit the pellets, brine shrimp did. Since the performance of his tank today, rubbed the paint from the paper-towel, bath towel was dark purple, the color, if it helps. He also had clear eyes, as if to study me. Whatcould have resulted in Tony's on my fish? Thank you!